Technical data

19
Technical characteristics:
Communication establishment time - 0.5 sec maximum;
Service band - 300-3400 Hz;
Speech intelligibility for the 300-3400 Hz band – at least Class 2 per GOST
16600-72 standards;
Communication establishment probability – 0.98;
Admissible signal-to-noise ratio - 3:1 (3 minutes – reception, 1 minute -
transmission);
Tolerable acoustic noise level - 120 dB;
Number of keys – up to 6;
Power supply – onboard circuit, 12V, 27V (21-31)V;
Radio set – VHF/UHF band;
Operating mode - simplex;
Weight - 2 kg ;
Volume – less than 2 cub. dm;
Power consumption – 1W .
Operating principles
The unit has been constructed as based on the principles of non-parametric signal
conversion.
At the input of the encryptor, the analog signal (voice) is converted into digital with
the employ of an 8-bit analog-to-digital converter. Cosine and sine digital filters are used to
determine the vector of the phase of the transmitted voice signal at a specific point of the
message. The envelope metering unit is used to measure the amplitude of the transmitted
signal, and it the delta-increment of the envelope that is subjected to further processing. After
the completion of above-indicated measurements (the phase and the envelope), the digital
sequence of parameters of the voice signal is put together modulo two with pre-created
pseudo-random sequence (generated by the cryptographic protection unit using the "Tiger"
algorithm of encryption) in accordance with a pre-input key. After that, it comes into the
synthesizer that is there to convert the resulting digital sequence into a form, convenient for
further processing. Then, the resulting digital flow is forwarded into the 8-bit digital-to-analog
converter.
As a result, at the output of the encryptor there appears an analog signal of the 500-
2850 Hz band, and goes into the linear amplifier that provides a normal loading for the radio
set.
On the receiving end of the communication channel, the information is processed in
the reverse order.
"Berkut-M" – a hardware product for portable radios for protection of voice
signals transmitted via VHF/UHF radio channels
"Berkut-M" encryptor provides encryption and decryption of telephone conversations
via VHF/UHF radio communication channels in the simplex mode, operating in a pair with
similar hardware products. And that guarantees protection of transmitted information against
unauthorized listening. The device is hooked up between the headset of the user and the radio.
When supply of power to the encryptor is interrupted, the radio operates in the
standard mode.